Method for producing compound fertilizer by high tower granulating

Abstract

The invention discloses a method for producing urea-base grain compound fertilizer by high-tower prilling, comprising pulping and prilling, where the pulping adopts three-step series continuous gradual cooling pulping method, comprising the steps of: adding fluxing agent and urea in a melting tank, melting the urea at low temperature and making the urea melt flow into the first stage mixing tank; in the first stage mixing tank, adding unreactable raw materials into the urea melt, and making the mixed melt flow into the second stage mixing tank; in the second stage mixing tank, adding in ammium phosphate and mixing for less than 4 min, and obtaining mixed melted pulp; spraying the mixed melted pulp through the double-speed rotating prilling nozzle of the high tower into a prilling tower to complete prilling. And it has advantages of low temperature operation, low energy consumption, low loss, good pulp fluidity, good operating environment. And the produced compound fertilizer grains are round, less broken and uniform.

Description

technical field [0001] The invention relates to a production method of granular compound fertilizers, in particular to an improved high-tower granulation method for producing urea-based granular compound fertilizers. Background technique [0002] At present, with the promotion and application of high-tower granulation technology, the production of compound fertilizer has jumped to a new level. Such as the Chinese patent, the patent number is CN03139601.1, which discloses a method and equipment for producing granular compound fertilizer by high-tower granulation. The urea-based compound fertilizer produced by high-tower granulation technology is popular among users because of its advantages of uniform nutrition, good water solubility, wide application range, and performance far superior to other types of fertilizers. The key technology of the compound fertilizer tower production is the pulping process, the slurry is too thick not only cannot flow in the pipeline, but also ca...

AI Technical Summary

Problems solved by technology

[0004] 1. High reaction temperature leads to nitrogen loss and poor operating environment

[0005] 2. The degree of polymerization of monoammonium phosphate is large, the viscosity of slurry is high, the load of stirring and granulator is increased, and the power consumption is large

[0006] 3. The viscosity of the slurry is high, it is easy to block the nozzle, and the product has many irregular particles

[0007] 4. The reaction temperature is high, the contact time is long, the foam is generated, and it is easy to be boiled

[0008] 5. The granulation temperature is high, the product bursts more, and it is easy to stick to the bottom of the tower

[0009] 6. Under the same cooling conditions, the product is easy to harden

[0010] 7. Except for urea, other materials need to be preheated and ground to consume steam

[0011] 8. Single-stage mixing has high stirring intensity, it is not easy to mix evenly, and it is easy to block the nozzle

[0012] 9. Single-stage mixing is unfavorable for processing the returned materials in production, and it needs to be equipped with ordinary production lines to digest the returned materials, and the investment cost is large